Kissinger, Gaylord M.; Wynn, Nicholas P.;

Process and composition

A method comprising purifying impure bisphenol-A by fractional melt crystallization in a falling film dynamic crystallizer.

• Electric fire simulator Oil film damper
• Intelligent key display Golf putting training device
• ITU/TDD modem Composite beam
• Transit rail lubricant applicator DNA encoding serotonin receptors
• Hydraulic drive type working vehicle Eyeglass headphones
• Pencil ignition coil assembly module Low-power integrated circuit memory
• Multi-phase charge holder Composite masonry block
• Lever hoist Bathtub-bathseat
• Motorized hide-a-bed actuating mechanism Process for preparing polyolefins
• Heat exchanger Prophylactic
• Human hematopoietic stem cell Capacity control device for compressor
• Protective layer for magnetic disk Biosensor
• Vehicle roof structure Apparatus for culturing animal cells
• Reversible automatic cell bypass circuit Quaternary alkynoxymethyl amines
• Ion-exchange group bearing composite membranes Athletic flooring system
• Buried cable removal apparatus Additive concentrates for distillate fuels
• Revolution sensor Optical plane waveguide
• Rotary switch Proportioner
• Wall module system Adhesive spreader
• Video signal processing device Positive drive system
• Transcutaneous energy transfer device Non-seating plate/fastener assembly
• Triazole antifungal agents Address translation apparatus
• Reversible ploughs

What is claimed is:

1. A method comprising purifying impure bisphenol-A by fractional melt crystallization in a falling film dynamic crystallizer.

2. A method in accordance with claim 1 wherein the purity of the purified bisphenol-A is better than about 99.80%.

3. A method in accordance with claim 1 wherein the purification is carried out in multiple stages.

4. A method in accordance with claim 2 wherein orthorhombic crystalline bisphenol-A is prepared.

5. The process in accordance with claim 1 wherein the per pass yield of bisphenol-A is at least about 75%.